Modulating Reactivity and Selectivity of 2-Pyrone-Derived Bicyclic Lactones through Choice of Catalyst and Solvent

Bioprivileged Molecules: Integrating Biological and Chemical Catalysis for Biomass Conversion

Further development of biomass conversions to viable chemicals and fuels will require improved atom utilization, process efficiency, and synergistic allocation of carbon feedstock into diverse products, as is the case in the well-developed petroleum industry. The integration of biological and chemical processes, which harnesses the strength of each type of process, can lead to advantaged processes over processes limited to one or the other. This synergy can be achieved through bioprivileged molecules that can be leveraged to produce a diversity of products, including both replacement molecules and novel molecules with enhanced performance properties. However, important challenges arise in the development of bioprivileged molecules. This review discusses the integration of biological and chemical processes and its use in the development of bioprivileged molecules, with a further focus on key hurdles that must be overcome for successful implementation.

Asymmetric Synthesis of [2.2.2]-Bicyclic Lactones via All-Carbon Inverse-Electron-Demand Diels-Alder Reaction

In this paper, a new cycloaddition between α,β-unsaturated aldehydes and coumalates realized under dienamine activation has been described. The reaction proceeds regioselectively with the distal double bond of the dienamine system acting as electron-rich dienophile. It leads to the formation of biologically relevant [2.2.2]-bicyclic lactones. Their functionalization potential has been confirmed in selected, diastereoselective transformations.

Proton-Detected Multidimensional Solid-State NMR Enables Precise Characterization of Vanadium Surface Species at Natural Abundance

Heterogeneous catalysts fulfill vital roles in industrial processes; however, the nature of the catalytic surfaces, typically either containing a low abundance of active sites or being amorphous in nature, leads to difficulties when attempting to study the structure of the active sites. In this work, we show how making use of fast MAS ssNMR allows one to efficiently detect well-resolved ¹H-detected spectra of heterogeneous catalysts. This approach was applied to study the structure of surface species resulting from the grafting of VO(OⁱPr)₃ onto a partially dehydroxylated silica using the surface organometallic chemistry approach. The use of ¹H sensitivity enabled detection of various hetero- and homonuclear correlation spectra in order to study the structure of this system and to resolve the structure of the grafted vanadium complex. More specifically, VO(OⁱPr)₃ grafts through both protonolysis and opening of siloxane bridges to generate a bis-grafted species.

A Robust Strategy for Sustainable Organic Chemicals Utilizing Bioprivileged Molecules

Biobased chemicals will inevitably be an important part of a sustainable organic chemical industry. Current efforts in biobased chemicals are largely driven by opportunistic chemical product targets requiring complete technology development from feedstock to final product for a specific molecule. To enhance the development of biobased chemicals, it is important to create strategies that can be more systematic and can leverage advancements across multiple final products. Discussed here is the concept of bioprivileged molecules, which are chemical intermediates that have the potential to be efficiently converted into a range of product molecules that can both directly replace existing petrochemicals and are novel molecules that impart enhanced performance properties in end-use applications.

Origins of complex solvent effects on chemical reactivity and computational tools to investigate them: a review

Origins of solvent-induced enhancement in catalytic reactivity and product selectivity are discussed with computational methods to study them.